For years, the method of obtaining wafers from a silicon ingot was by using diamond wire cutting, which is a mechanical process. Although equipped with nearly fully-automated production equipment, the production lines in the industry still inevitably generate considerable wafer material loss, and considerable amount of water, electricity and consumables (such as diamond cutting fluids and metal cutting wires, etc.) are also required. Therefore, the wafer cutting process has become one of the key processes for wafer processing in pursuit of lower cost.
In addition, regarding the process of manufacturing gallium nitride light-emitting diodes (LEDs) on a surface of a substrate, sapphire is the most common substrate. However, the processing of sapphire is relatively difficult and time-consuming due to the intrinsic properties of the material. There is a great demand of technologies which is capable of replacing existing processes. Silicon has been extensively used in various semiconductor, electro-optical, photovoltaic industries for years. Silicon has thus emerged as one of the alternative materials to replace sapphire substrate. In order to improve the material properties such as the differences in lattice constant as well as the thermal expansion coefficient between the LED materials (such as gallium nitride) and the silicon substrate, the epiaxial growth of the LED material should be thoughtfully controlled. Processing and even making patterns on the silicon substrate surface might offer a solution to this technical challenge. The lithography process with photo masks is currently used to create patterns on the surface of a silicon substrate. However, the facility and operational costs of the lithography process for putting a pattern on silicon substrate surfaces are extremely high, and it makes the cost reduction of LED products difficult.
In order to overcome the drawbacks in the prior art, the present invention introduces a novel cost-effective method of substrate processing. The particular design in the present invention not only solves the aforementioned problems, but is also easy to implement. Thus, the present invention has utility for the industry.